Sand Core Mold

[Toolman]

This mold will form a sand core that creates a passage thru a sand casting during the pour. When the casting cools down, they knock the sand loose and pour it out the hole.

 

[lbhsbz]

How do you fill it with sand (and make sure it's full) ?

 

[Toolman]

How do you fill it with sand (and make sure it's full) ?

If you look at the far end of the long channel you will see a smaller channel that is 3/8 in diameter when both halves are bolted together. That is where the sand is poured in. At the other end of the channels both long and short you’ll see a horseshoe shaped notch that act as a vent. So they fill it with sand under pressure until they see sand flowing out of those vents. The foundry will carve a groove connecting the vent to the end of the channel of a size they choose depending on the kind of sand they’re using.

 

[lbhsbz]

If you look at the far end of the long channel you will see a smaller channel that is 3/8 in diameter when both halves are bolted together. That is where the sand is poured in. At the other end of the channels both long and short you’ll see a horseshoe shaped notch that act as a vent. So they fill it with sand under pressure until they see sand flowing out of those vents. The foundry will carve a groove connecting the vent to the end of the channel of a size they choose depending on the kind of sand they’re using.

Ahh...It didn't look like the vent connected to the mold cavity....that's what I was missing. How did you cut the threads in the mold?

 

[Toolman]

Those are milling step over passes ( Kellering). Using a ball nose end mill, the machine ramps down one side and up the other side like a skateboarder on a (half pipe I think it’s called) while moving over around .015 per pass looking like threads.

 

[Toolman]

Update on this job. So we just found out that we’re not getting paid for this mold. Apparently, the computer model that they created and gave me was wrong. They want me to re-cut another set. So I felt bad for them and I gave him a slight discount for another set. They responded with, “We’ve decided you will cut another set for free if you want to be paid for the first set”. I’ve been doing business with this company for 25 years. The good old boys that used to run the plant are now all retired and new guys are running it and this is their way. So I informed them that we will not be doing business anymore.

 

[arch stanton]

sometimes customers need to be fired to make room for ones that are more profitable and less a PITA